when you fund it;As with everything in tax law, it's important to follow the rules. To claim a charitable deduction on your tax return, you must itemize your deductions on your Sch A of 1040 , if not, you can nnot claim the deduction; Cash donations, no matter the amount, must be substantiated by a bank record such as a canceled check or credit card receipt, clearly annotated with the name of the charity or in writing from the organization.